HVO 2009 Annual Environmental Management Report - Final

Coal & Allied – Hunter Valley Operations
3.9 BLASTING
3.9.1 Environmental Management
Operational Limits
The objective of blasting operations is to ensure that optimal fragmentation is obtained whilst minimising dust
generation, adhering to safety standards and conforming to EPL criteria for vibration and overpressure.
Hunter Valley Operations’ EPL 640 states:
L7.1 The airblast overpressure level from blasting operations carried out in or on the premises must not
exceed:
(a) 115dB(L) for more than 5 per cent of the total number of blasts during each reporting period;
and
(b) 120dB(L) at any time.
At any residence or noise sensitive location that is not owned by the licensee or subject of a private
agreement between the owner of the residence or noise sensitive location and the licensee as to an
alternative overpressure level.
L7.2 The ground vibration peak particle velocity from blasting operations carried out in or on the premises
must not exceed:
(a) 5mm/s for more than 5 per cent of the total number of blasts carried out on the premises
during each reporting period; and
(b) 10mm/s at any time.
At any residence or noise sensitive location that is not owned by the licensee or subject of a private
agreement between the owner of the residence or noise sensitive location and the licensee as to an
alternative overpressure level.
Blast Monitoring
HVO operated a network of six Datamasters Version 6 (V6) blast monitoring units in 2009 (refer to Figure 70).
These are located at nearby privately owned residences and function as regulatory compliance monitors.
These monitors are located at:
Jerrys Plains Village;
Wandewoi;
Maison Dieu;
Cheshunt East;
Warkworth School; and
Moses Crossing.
The blast vibration units continuously screen for ground vibration. All captured blasts are automatically
recorded to a computerised database that is backed up daily. These instruments can be monitored from the
main office, allowing blasting results to be viewed immediately after the blast.
HVO also maintains a number of monitors to assist internal blast vibration and overpressure management.
These units are strategically located to provide vital information on blast performance. This information is then
utilised for further improvement in mine production as well as vibration and overpressure levels at surrounding
residences.
AEMR 2009 123